Improvement in straightening and drying lumber



R. S. GILLESPIE.

STRAIGHTENING AND DRYING LUMBER. No.185,742. Patented Dec.26, 1876.

m mm N-PETEkS, PNOTO-LITHOGRAFHM. WASHINGTON. D C.

gggw UNITED STATES PATENT OFFICE.

RICHARD S. GILLFSPIE, OF NEW YORK, N. Y.

IMPROVEMENT lN STRAIGHTENING AND DRYING LUMBER.

Specification forming part of Letters Patent No. 185,742, dated December26, 1876; application filed November 11, 1876.

To all whom it may concern Be it known that I, RICHARD S. GILLEsPIE, ofNew York city, in the State of New York, have invented certain new anduseful Improvements Relating to Straightening and Drying Lumber, ofwhich the following is a specification Thin lumber is susceptible ofbeing thoroughly dried by rapid treatment, but with great liability tocurl. Great quantities of such lumber are required in the manufactureofcigar-boxes and analogous articles. I have devised an apparatus inwhich the wood is passed continuously through a series of metal rolls,which hold it rigidly straight while heat ed as highly as may be safelydone, with provisions for conveying away the moisture which escapes.

The following is a description of what I consider the best means ofcarrying out the invention.

The accompanying drawings form a part of this specification.

Figure 1 is a section through the blowing and air-heating means. Fig. 2is a side elevation of the straightening machinery. Fig. 3 is a portionof the same in section. v Fig. 4 is an end elevation of the same. Fig. 5is a cross section on the line S S in Fig. 2.

Similar letters of reference indicate corresponding parts in all thefigures.

A is a fan-blower, which forces the air in a liberal current through theseveral chambers in B, which is an air'heating stove or furnace capapleof raising the air to atemperature of-say, 400 Fahrenheit. The air thusuni formly and highly heated is conducted through a pipe, 0, into aspace below a perforated plate or horizontal partition, D, which causesthe hot air to be distributed nearly uniformly among the rolls and uponthe green lumber which is being treated.

E E 850., are a series of smooth iron rolls, preferably nickel-plated,cased in copper or otherwise very smoothly and durably coated with ,anon oxidizable metal or material. Gear-wheels e e, 850., are fixed onthe overhanging ends of these rollers. Intermediate gear-wheels h,mounted on fixed studs, communicate the motion from one to another. Oneof the main rolls carries a pulley, F,

which receives motion through a belt, G, from a steamengine or otherconvenient power.

The gear-wheels e 6 6 &c., are not uniform in size, the last of theseries being smaller than the first, and inducing a more rapid rotationof their rolls. All the rolls E E &c., run in rigidly-supported bearingsarranged in a right line.

Heavy top-rolls I are mounted above, each bearing on one of the rolls EE 850. The trunnions or prolonged axes of these heavy rolls I are heldin slots in the framing or housing K, with freedom to rise and sink, aswill be obvious.

The whole set of rolls is inelosed within a box, K, the top of which isinclined, as shown, and communicates with a flue, L, which may lead awayto the chimney, or may, if preferred in any instance, communicatearound, and after passing the air in contact with some desiccatingmaterial may lead out again to the fan A.

A low but wide orifice is provided at each end of the ease K at theproper level, one to receive the thin lumber to pass the rolls and theother to allow its discharge. Each is guarded by a hinged door, M, whichcloses by gravity, and is made sectional, three sections beingrepresented, but the number may be increased at will. When narrow piecesof lumber are introduced they open only the central section or sections.When wider pieces are passed in they open the whole.

The air received by the fan A may be pre' viously subjected to contactwith desiccating materials and deprived of most of its moisture evenwhen cold fresh air is received. This is more important when the wholeor any portion of the air is passed around more than once.

The hot and dry air is distributed by the perforated plate 1) and causedto rise gently and quite uniformly. It keeps all the rollers at a hightemperature, and also acts directly on the lumber in its passage betweenthem.

Successive increase in the velocity of the pairs of rolls induces eachpiece of lumber to move away from its successor and leave a considerablespace between, through which the hot air rises freely. It rises, also,freely past each side or edge of the lumber.

The size of the rolls and their distances apart should be so graduatedto the probable lengths of the pieces of lumber to be treated that eachpiece shall be subjected to the action of more than one pair of rolls atthe same time. The difi'erences in the velocities of the rolls willcompel one or both to slip. This slipping polishes the lower surface.

In cases where the expense will be warranted, a fan or otherblowing-machine may be mounted as an exhaust, in connection with theflue or escape L. In such case the speed of the blowing-fan and of theexhausting-fan should be so graduated that the air will be neitherforced out or drawn in through the openings which admit and dischargethe lumber. The slots which guide the upper rollers need not be made toextend through the outer case or box K. They may be in an insideframing.

Provisions may be made for making increased pressure on the rollers, orfor holding up one or all the top rolls to the height required by thethickness of the lumber. Steam may be introduced in the interiors of oneor both sets of rolls; but I propose, in most instances, to maintain atemperature higher than that of ordinary steam. superheated steam may beintroduced in the rolls, and also may be mingled with the air passedthrough the apparatus. With proper precautions in regard to fire, aportion, or the whole, of the gaseous products of combustion fromthe-stove B maybe mingled with the air passing through the apparatus.

1 esteem it of great importance that the airheating furnace and itsaccessories shall be in another apartment or in another building, fromthat in which great quantities of the thin and thoroughly dried lumberare being handled.

The apparatus should be sufficiently long, and the traverse of thelumber through it should be sufliciently slow, to allow the material tobe thoroughly dried. In some cases,

however, the material may, after passing once through, and while itstill remains heated, be

carried around and passed through themachine a second time.

The liability of all thin lumber to curl or warp in drying is familiarto every observer. This is peculiarly felt with some kinds of lumberwhich might otherwise be made very useful. Some modes of manufacturingthe thin shapes tend to leave it strongly curled. I profor to take thelumber very fresh from the saw or from the cutting instrument. In caseswhere the wood is steamed at some stage of its manufacture, it should bepassed into my apparatus in its fresh and steamy condition.

The wood issues from my exit-doors absolutely straight. The increasedpressure, when desired, on the top rolls, may be applied by springs withwedge or screw adjustments, or, preferably, by weighted levers. Meansmay be provided for increasing the pressure on the whole at once.

I claim as my invention- 1. The method described of straightening anddrying lumber, by passing it between a series of hot metal rollers inabath of hot air or gas, as herein specified.

2. The method described of simultaneously straightening, drying, andpolishing lumber, by passing it between a series of hot rollers in abath of hot air or gas, with the rollers slipping on one of itssurfaces, as specified.

3. The drying and straightening apparatus, composed of the blowing meansA, air-heating means B, passage (3, rollers E I, combined in a longseries, and casing K. all arranged and serving, in combination, totraverse, hold, heat, and dry the lumber, as herein specified.

4. The door M, in combination with thecasing K, rollers E I,air-distribute! D, airheater B, and blower A, as and for thepurposes'herein specified.

In testimony whereof I have hereunto set my hand this 10th day ofNovember, 1876, in the presence of two subscribing witnesses.

RICH. S. GILLESPIE.

Witnesses:

THOMAS D. STETSON, CHARLES C. S'rnrson.

